Wire enameling apparatus



April 3, 1956 c. WAGNER ETAL WIRE ENAMELING APPARATUS 2 Sheets-Sheet 1 Filed April 8, 1954 INVENTORS Clarence Wagner BY JO oger AM z. ATTORNEYS y Essenb awn-4 Modk April 3, 1956 c. WAGNER ETAI- 2,740,373

WIRE ENAMELING APPARATUS Filed April 8, 1954 2 Sheets-Sheet 2 PEG. 2

Cl INVENJVORS orence ogner 40 s B Joy Essenbo er ATTORNEYS United States Patent WIRE ENAMELING ARPARAH US .Clarence Wagner and .Jay I Essenbager, Muskegon, Mich., assignors to Anaconda Wire and Cable Company, a corporation of Delaware Application April 8, 11954, :Ser ial N0a42z1 800 7 Claims. (Cl. '1'I8'.68)

'dried thereon. The term "-ename'las used herein refers to all coatings that are applied to the *wire ="in liquid form and thereafter are dried or otherwise solidified to form an impervious film of insulation thereon. Such coatings may be applied to the bare metal wire crate 'afibrous' coveringor serving surrounding the Wire, and the thicknessof the coating may beva'ried by applying any desired number of successive-layers "ofithe-coating enamel. in applying such coatings, however, difficulty "is frequently encountered in obtaining a coating of uniform thickness. The coating is usually applied 'withspecial apparatus that includes an applicator for apply'ing"the coating of liquid enamel to the wire and an oven for baking the enamel on the wire. remove excess of liquid enamel "from the surface of'the wire prior'to the baking operation, However, the'wiper means heretofore used "have not -been altogether "satisfactory for in some cases "the wiper may remove too much or too little of the enamel, and in other cases may damage previously applied insulation by scratching of the underlying enamel 'or -abrading er -the"underl ying fibrous covering surrounding the Wire. -In the former cases either the enamel film is excessively'thin 'or even discontinuous or it is undesirably heavy and iirregular; and in the latter cases the 'quality and the dielectric properties of the insulation 'are impaire'd. It is to'this pro'blemthat 'ourinew inventionfis addressed, and, accordingly, we'have devised apparatusincluding.wipizrgmeans by which coatings of enamel'may be applied'towire speedily and efiiciently with optimum thickness and .uniformity.

The apparatus we have .devised includes an enamel applicator for applying a coating of "liquid enamel to Wiper means are provided "to e surface of a moving wire, a drier "for "dryingthe coating of liquid enamel 'on the wire, and means for guiding the wire from the enamel applicator to "the 'drier. An absorptive-surface wiper roll and an '.absorptive-'surffaced blotter roll are disposed between theiapplicator and the drying oven in contact with each other and with the moving Wire. blotter roll at a speed substantially corresponding Ito the linear rate of travel of the 'movingwire, 'and 'in the same direction as "the moving'w'ireiwherelit is in' contact there- Means are provided *for *rotatin'gfthe with. The wiper roll in contact'withtheiblotter roll is Y rotated in the opposite direction by the rotation of "the blotter roll. Thus the wiper roll serves to remove excess enamel from the surfaceof the wire substantially by a brushing action and'the blotter roll"servesto"remove excess enamel from the surface "of the'wirvsubstantially by a blotting action. Additionally, the wiper roll and 2 the blotter roll mutually squeeze excess enamel from the absorptive surfaces :of these two rolls.

:The wiperzroll-and the blotter roll bothadvantageously icomprise a'plurality :of :annular washers of felt axially :aligned-ona shaft to format cylindrical roller having an aabsorptiveesurface ofifelt. Ametal washer is provided .on "the shaft at each end of the felt roller, *and nuts in threaded engagement with .the shaft :are provided for adjustably :crov'vding the metal washers against the felt washers, whereby the hardness and absorptive qualifies ot the ifelt roller may be controlled.

iA preferred embodiment of the invention is described below with Jeference to the accompanying drawings, in which Fig. 1 is a side view of the new :apparatus;

Fig. 2 is a plan view .of the apparatus shown in Fig. 1;

Fig. 3 is an enlarged sectional view taken substantiallyalong the "line 33 of Fig. 2;

Fig. 4 is a fragmentary view from the front of-one 'of the grooved metal rollers shown'in Fig. 3;

Fig. '5 is a sectional view of one end of the felt wiper roll taken substantially along line 5-5 of Fig. 2;'and

Fig. 6 is -a cross section of the felt wiper roll taken along-line 6-6 of Fig. 5.

Referring first to Fig. '1, theern'bodiment of our invention shown-in the drawings comprises an enamel appli- "cator indicated generally at 10 for applying a coating -of -liquid'enarne1 to'a plurality of'wires 11,wiper means indicated generally at 12 for removing excess liquid enamel from the'wire, an oven '13'for drying 'or baking =th e liquid enamel 'on "the surface of the wire, and wind=up reels 14 for receiving the freshly enameled wire. 7 n

The enamel applicator 10 and the wiper means 12 are mounted on horizontalframe members "15 v'lhichare supported by vertical posts '16. 'The ename'lapplicator "'10 comprises one *or more dip pans 1'7 and "17.11 each adapted to-contain a 'body of the liquid enameL'a plurality of sheaves or guides "18 each adapted to receive onewire ll'and immerse it below the surface of the liquid enamel in the 'dip pan 17 or with which it .is associated, and guide ro'llers '19 disposed in "each 'of the dip pans 17 and 17a to support the wires where they emerge fromt'he body of enamel in the 'dip pans. Wire which has received a first or prime coat of enamel by being 'passedthrough one of the dippans 17 mayfbebrought back 'over the top of the oven and be .passed through the other dip pan 17a "for the :purpose of giving it a-secon'd'co at with enamel of somewhat different composition. The :dip pans 17 and 17a are mounted on lateral members 20 .and may be of varying lengths 'in order toqprovide -for irnrnersionof the wire in the liquid enamel for varying periods of time. .The sheaves 318 are partially immersed in..the'bod y of liquid enamel and are 'rotataibly mounted on shaftsf21 which, .in turn, are 'supported'iby.brackets 22 secured to'the horizontal frame members 15, .The wires 11, each received in thegroove in one of the sheaves .18, are spaced from each other and are ,guided individually into the body of liquid enamel .bysaid sheaves 18. 'Each wire, after passing under one of Lthe sheaves 18, .emerges from the liquid enamel .heavily coated with said enamel. The wire then passes over .the .guide rollers .19 disposed in the dip pans 17 and thence to the-wiper means'12 for removal of the excess enamel 'from .the 'wire.

The wiper means12'comprisesa pair of grooved metal rolls 24, a wiper roll 25, and a blotter roll 26. The metal rolls 24 are formed with a plurality of 'V-shaped eripheral grooves 27 as' 'best shown "in Fig. 4), each groove being 'laterally spaced from the-adjoining groove by a distance corresponding to the lateral distance between the grooves of the sheaves 18; and each roll groove 27 receives one of the wires 11. The grooved metal rolls 24 are rotatably mounted in metal frames 2% which are adjustably suspended from transverse bars 29. The transverse bars 29 are, in turn, adjustably mounted on side supports 30 secured to the horizontal frame members 15. As best shown in Fig. 3, the position of the metal rolls 24 may be adjusted vertically by a push-pull screw system comprising stud bolts 31 secured to the frames 28 and cooperating locking bolts 33 threaded through the transverse bars 29. Lateral adjustment of the metal rolls 24 is permitted by the provision of lateral slots in the transverse bars 29 through which the stud bolts 31 extend; and lateral adjustment of the bars 29 is permitted by corresponding slots therein for receiving the bolts 35 by which these bars 29 are attached to the, side supports 39. The adjustable mountings of the frames 28 and the transverse bars 29 permit the grooved metal rolls 24 to be positioned so that the grooves 27 are in alignment with the corresponding spaced sheaves 18, and so that one of the grooved metal rolls supports the wires 11 from below while the other presses down on them from above, as shown in Figs. 1 and 3. Felt wiper strips 36 secured to each of the metal frames 28, and a metal doctor blade 37 secured to the second of the two successive frames 28, may be provided to remove from the groove metal rolls 24 such excess liquid enamel as is transferred thereto from the strands of wire 11.

The grooved rollers 24 serve to remove from the wire the gross excess of enamel adhering thereto, and they insure that the entire surface of the wire is completely wet with the liquid enamel. width of the grooves 27 relative to the diameter of the wire determines approximately the amount of enamel which will be left on the wire. In addition, the grooves spread the enamel evenlyover the surface of the wire, and help to insure that pin holes or other imperfections caused by minute bubbles, particles of dust, or the like, which ordinarily would prevent the enamel from wetting all of the surface of the wire, are eliminated.

To assure the establishment of an enamel film of optimum thickness and to remove the final excess of enamel therefrom, the strands of wire 11 are thereupon brought into contact with the wiper roll 25 and the blotter roll 26. The wiper roll and the blotter roll are provided with an absorptive surface of felt, pile fabric or a similar material capable of removing from the wire the excess of liquid enamel thereon while leaving on the wire a layer of the enamel of uniform and optimum thickness. The absorptive surfaces of the wiper roll and the blotter roll are advantageously formed by a plurality of annular felt washers or rings axially aligned and mounted in abutting relation on a metal shaft. This construction as it is applied to the blotter roll 26 is best shown in Figs. and 6. A plurality of annular felt washers 40 are mounted in a row on a metal shaft 41 that is threaded at both ends. Metal washers 42 are disposed on the shaft 41 at each end of the row of annular felt washers 40, and nuts 43 in threaded engagement with the shaft are disposed at each end of the shaft adjacent the metal washers 42. By tightening (or loosening) the nuts 43, the metal washers 42 and the annular felt rings 40 can be adjustably crowded together so that the relative hardness and absorptive qualities of the felt on the roll can be controlled. Similarly, the wiper roll 25 is provided with an absorptive surface 44 advantageously formed by a plurality of annular felt washers axially aligned on a shaft 45. The hardness and absorptive qualities of the felt surface 44 of the wiper roll 25 may be regulated by means of metal washers 46 and nuts 47 disposed at the ends of the shaft 45 in the same manner as the washers 42 and nuts 43 regulate those qualities of the blotter roll 26.

For the most effective utilization of the absorptive properties of the absorptive-surfaced blotter roll 26, it

The depth and justably mounted (by is advantageous to rotate the blotter roll so that, at the point of contact with the wires, its surfacetravels in the same direction and at the same speed as the wire. Thus,

at said point of contact, the moving strands of wire and the rotating blotter roll will be momentarily relatively stationary with respect to each other and, if these conditions are met, the excess liquid enamel will be removed from the wire by this roll substantially by absorption, or blotting action, rather than by mechanical scraping orrubbing. In particular, the peripheral velocity of the blotter roll 26 should not at any time exceed the linear velocity of the wire 11 in order to prevent the roll 26 from reapplying excess enamel to the wire. To this end the. shaft 41, supported in self-aligning bearings 48, is connected by means of an arbor 49 and a pin 50 to a sprocket 51 that is driven by a motor 52 through a variable speed drive mechanism 53. By suitable adjustment of the mechanism 53, the shaft 41 can be made to rotate at an angular velocity corresponding to the linear velocity of travel of the moving wire. To insure rotation of the felt washers 40 without slippage on the shaft 41, they are keyed together by rods 54 that extend through holes formed in their annular bodies and also in the bodies of the metal washers 42; and the metal washers in turn are connected by a key and keyway 55 to the shaft 41.

The rotation of the blotter roll 26 causes the wiper roll 25 in contact therewith to rotate so that, at the point of contact between the wiper roll and the wire 11, the absorpive surface of the wiper roll is moving in the direction opposite to the direction of travel of the wire. Thus, as the wire travels from the grooved metal rolls 24 over the wiper roll 25 and the blotter roll 26, the excess enamel adhering to the wire is removed therefrom by the combined brushing action of the counterrotating wiper roll and the blotting action of the forward-rotating blotter roll. Moreover, in addition to the relative hardness or compactness of the absorptivesurfaced wiper roll 25 and blotter roll 26, and the correlation between the direction and speed of rotation of these rolls and the linear speed of travel of the wire 11, still another factor affects the amount of liquid enamel that can be absorbed by these two rolls, namely, the extent to which the absorptive surfaces of the rolls are allowed to remain saturated with enamel. The excess liquid enamel transferred from the wire 11to the absorptive surfaces of the wiper roll 25 and the blotter roll 26 would soon completely saturate these rolls and interfere with their proper functioning unless an equivalent quantity of enamel were continuously removed therefrom. By so removing the excess liquid enamel from the rolls 25 and 26, the extent of saturation with enamel and hence the absorptive characteristics of the absorptive surfaces are maintained at an optimum level so that a predetermined optimum amount of enamel can be left on the wire 11.

To maintain said optimum extent of saturation of the rolls 25 and 26, the two rolls are maintained in firm contact with each other in order to squeeze from the wiper roll and the blotter roll the undesired excess enamel held thereby. The wiper roll 25 is rotatably mounted in bearings carried by hearing supports 56 which are adbolts extending through slots) to permit the wiper roll to be moved toward or away from the blotter roll so that the force with which the wiper roll bears against the blotter roll can be regulated. By appropriate adjustment of the force with which the blotter roll 26 bears against the wiper roll 25, and of the hardness or compactness of the absorptive surfaces of these rolls, the amount of liquid enamel allowed to remain on the wiper roll and the blotter roll, and, therefore, the relative saturation and absorptive characteristics of the rolls, can be closely controlled.

In order to insure that the extent of saturation of the wiper roll 25 and the blotter roll 26 with enamel will be uniform throughout their length, .the force with which the blotter roll bears against the wiper ro'll should also the uniform throughout the length of the respective rolls. Therefore, to prevent undesirable deflection of these'rolls fromtheirdesigned axes of rotation, the wiper roll and theblotterroll 26, if very long, are-advantageously "supported at intermediate points 58.

The enamel removed from-the wire "11 by the grooved metal rolls 24 and by the absorptive-surfaced rolls 25 and 26 fall from these rolls into a drip pan 59 disposed therebeneath. The drip pan 59 is provided with a drain 60 so that the accumulated enamel may be withdrawn therefrom for return to the body of liquid enamel in the dip pans 17 and 17a.

The strands of wire 11, having been uniformly coated with a film of liquid enamel of optimum thickness, travel through the drying oven 13 in which the enamel is baked or dried, a the case may be, to form a tough impervious film on the wire. The length of the oven should be sufiicient to insure that the film of enamel is thoroughly dried and hardened before the wire emerges therefrom.

On emerging from the drying oven 13, the wire is led back either over or under the oven to one of the dip pans 17 or 17a, to apply additional coats of enamel thereto. When a sufiicient number of coats have been applied, the wire is wound up on the reel or spool indicated at 14.

As will be seen from the foregoing description of the apparatus of our invention, it is possible with our novel enamel applying apparatus to form on electric wire an insulating film of enamel of optimum thickness and of uniform character and insulating properties.

We claim:

1. Apparatus for applying a coating of enamel to a moving wire comprising an applicator for applying liquid enamel to the surface of the wire, a drier for drying the coating of liquid enamel applied to the wire, an absorptive-surfaced wiper roll in contact with the moving wire between the drier and the applicator, and an absorptivesurfaced blotter roll in contact with the moving wire and with the wiper roll between said wiper roll and the drier, said blotter roll being rotated at a peripheral speed substantially equal to the rate of travel of the moving wire and in the direction corresponding to the direction of movement of said wire where it is in contact therewith and said wiper roll being rotated by said blotter roll in the opposite direction.

2. Apparatus for applying a coating of enamel to a wire comprising an applicator for applying liquid enamel to the surface of the wire, a drier for drying the liquid enamel coating applied to the wire, a succession of grooved metal rolls in contact with the moving wire between the applicator and the drier, each of said grooved metal roll having a V-shaped circumferential groove adapted to receive the moving wire, an absorptive-surfaced wiper roll in contact with the moving wire between the drier and the grooved metal rolls, an absorptive-surfaced blotter roll in contact with the moving wire and with said wiper roll between the wiper roll and the drier, and means for rotating the blotter roll at a peripheral speed substantially equal to the rate of travel of the moving wire and in the direction corresponding to the direction of movement of said wire where it is in contact therewith, said wiper roll serving to remove excess enamel from the surface of the wire substantially by a brushing action and said blotter roll serving to remove excess enamel from the surface of the wire substantially by a blotting action, said wiper roll and said blotter roll serving mutually to squeeze excess enamel from the absorptive surfaces of these rolls.

3. In apparatus for applying a coating of enamel to a moving Wire comprising a dip pan adapted to contain a quantity of liquid enamel, an oven for drying the enamel coating applied to the wire, and means for guiding the @moving \wire through liquid enamel contained ,in -.the ;dip ,pan and thence into=and throughthe drying oven, theimprovement comprising an absorptive-surfaced wiper roll -.disposed between :the drying o-venvand the dipppan and in contact with the moving wire, and an absorptive-surfaced blotter roll inacontact with and pressing lfinnlyragainst said wiper roll and said moving wire,.said blotter.roll bethe moving wire through liquid enamel contained in the dip pan and thence through the drying oven, a wiper roll in contact with the moving wire between the drying oven and the dip pan, a blotter roll in contact with the moving wire between the wiper roll and the drying oven and bearing firmly against said wiper roll, said blotter roll comprising a plurality of annular felt washers axially aligned on a rotatable shaft, and means for rotating said blotter roll at a speed such that the surface thereof moves at substantially the same rate and in the same direction as the moving wire in contact therewith, said wiper roll serving to remove excess of liquid enamel from the moving wire substantially by a brushing action and said blotter roll serving to remove excess enamel from the moving wire substantially by a blotting action, said wiper roll and said blotter roll serving mutually to squeeze excess liquid enamel from the surfaces of these rolls.

5. Apparatus for applying a coating of enamel to the surface of a moving wire comprising a dip pan adapted to contain a quantity of liquid enamel, an oven for drying the enamel coating applied to the wire, means for guiding the moving wire through the liquid enamel contained in the dip pan and thence through the drying oven, a wiper roll in contact with the moving wire between the dip pan and the drying oven, a blotter roll in contact with the moving wire and bearing against said wiper roll between the wiper roll and the drying oven, said wiper roll and said blotter roll each comprising a plurality of annular felt washers axially aligned on a rotatable shaft, and means for rotating said blotter roll at a peripheral velocity substantially corresponding to the speed of travel of the moving wire and in the same direction as said wire where it is in contact therewith, said rotation of the blotter roll rotating the wiper roll in the opposite direction, said wiper roll serving to remove excess enamel from the moving wire substantially by a brushing action and said blotter roll serving to remove excess enamel from the wire substantially by a blotting action, said wiper roll and saidiblotter roll serving mutually to squeeze such excess of enamel from the felt surfaces of these rolls, whereby the wire is coated with a film of liquid enamel of optimum thickness prior to baking the film of enamel on the surface of the wire.

6. Apparatus for applying a coating of enamel to the surface of a moving wire comprising a dip pan adapted to contain a quantity of liquid enamel, an oven for drying the enamel coating applied to the wire, means for guiding the moving wire through the liquid enamel contained in the dip pan and thence through the drying oven, a felt-surfaced wiper roll in contact with the moving wire between the dip pan and the drying oven, a felt-surfaced blotter roll bearing firmly against said wiper roll and in contact with the moving wire between the wiper roll and the drying oven, said wiper roll and said blotter roll each comprising a plurality of annular felt washers axially aligned on a rotatable shaft and adjustable means for compressing said washers axially together, whereby the hardness and absorptive qualities of the felt surfaced rollers may be controlled, and means for rotating said blotter roll at aperipheral velocity substantially corresponding to the speed of travel of the moving wire and in the same direction as said wire where it -is in contact therewith.

7. Apparatus according to claim 6, characterized in that at least one key rod extends through the annular body of each of the felt washers arrayed on said shaft, thereby preventing rotation of said washers relative to one another.

References Cited in the file of this patent UNITED STATES PATENTS Grnnder et a1. Dec. 11, 1883 Zavodofi Feb. 16, 1932 Convers May 8, 1934 Kress Aug. 7, 1934 Lade Jan. 9, 1940 Logan Oct. 3, 1944 

1. APPARATUS FOR APPLYING A COATING OF ENAMEL TO A MOVING WIRE COMPRISING AN APPLICATOR FOR APPLYING LIQUID ENAMEL TO THE SURFACE OF THE WIRE, A DRIER FOR DRYING THE COATING OF LIQUID ENAMEL APPLIED TO THE WIRE, AN ABSORPTIVE-SURFACED WIPER ROLL IN CONTACT WITH THE MOVING WIRE AND BETWEEN THE DRIER AND THE APPLICATOR, AND AN ABSORPTIVESURFACED BLOTTER ROLL IN CONTACT WITH THE MOVING WIRE AND WITH THE WIPER ROLL BETWEEN SAID WIPER ROLL AND THE DRIER, SAID BLOTTER ROLL BEING ROTATED AT A PERIPHERAL SPEED SUBSTANTIALLY EQUAL TO THE RATE OF TRAVEL OF THE MOVING WIRE AND IN THE DIRECTION CORRESPONDING TO THE DIRECTION OF MOVEMENT OF SAID WIRE WHERE IT IS IN CONTACT THEREWITH AND SAID WIPER ROLL BEING ROTATED BY SAID BLOTTER ROLL IN THE OPPOSITE DIRECTION. 